In glassware molding, molding machines, such as the type commonly known as I.S. machines, are employed comprising a number of side by side forming sections, each for producing a respective sequence of articles.
Each forming section comprises a rough mold, normally with one or a number of adjacent mold cavities, each for receiving a glass gob and forming a respective semifinished article, which is then transferred by an inverter to a mold cavity of a finish mold to be transformed into the finished article.
Each mold normally comprises a bottom shell; and two lateral half-molds movable with respect to each other and the relative bottom shell between a closed position, in which the lateral half-molds and the bottom shell define the mold cavities, and an open position in which enable the removal of the semifinished or finished articles from the mold.
To facilitate distribution of the glass inside the mold and removal of the article from the mold to obtain articles of consistent surface quality and shape, the molds are cleaned and lubricated regularly. This substantially consists in removing scale from the inner surfaces of the mold contacting the glass, and coating the surfaces with a release agent or lubricant, e.g. graphite-based, to prevent the glass from sticking to the inside of the mold and so producing flaws in the surface or shape of the semifinished or finished article when it is removed from the mold.
The surfaces are normally lubricated either by hand, or by spraying the lubricant on using spray heads that can operate with the mold open or closed.
Whichever the case, given the high temperature of the molds, applying, and particularly spraying, lubricant onto the inner surfaces of the molds inevitably produces emissions which, together with the powdery scale removed, contaminate the surrounding area by settling on machine parts in the vicinity of the molds, thus calling for regular cleaning, and also make for an unhealthy workplace.
The work carried out on each mold is relatively time-consuming and increases in proportion to the number of machine sections, with the result that downtime and the length of time workers are exposed to such work bear heavily on the production cycle.